Examples of conventional refrigeration cycle apparatuses capable of a simultaneous cooling and heating operation include, for example, an air-conditioning apparatus applied to a multi-air-conditioning apparatus for a building, or other purposes. Some of such air-conditioning apparatuses use a water heat exchanger as an outdoor heat exchanger (a heat source side heat exchanger).
As an example of the above configuration, conventionally-proposed structures include “a water-cooled air conditioning apparatus in which a refrigeration cycle is structured by sequentially connecting together, by refrigerant pipes, a capability-variable compressor, a four-way valve, an outdoor side water heat exchanger exchanging heat between refrigerant and cooling water, a pressure reducing device, and an indoor side air heat exchanger equipped with an indoor fan, the water-cooled air conditioning apparatus including a controller configured, when a room temperature detected by a room temperature sensor has reached a level close to a set temperature, to reduce the operating rotation speeds of both the compressor and the indoor fan depending on the temperature difference between the detected room temperature and the set temperature, the water-cooled air conditioning apparatus including a water volume regulating valve configured to control conduction and flows of the cooling water conducted to the outdoor side water heat exchanger, the controller being configured to control the opening degree of the water volume regulating valve corresponding to the operating rotation speeds of the compressor and the indoor fan” (see Patent Literature 1, for example).
Further, another conventionally-proposed structure is “a water heat source air-conditioning system in which a detour pipe is connected to a heat source water circuit to allow communication between the detour pipe and the heat source water circuit, the detour pipe is provided with a flow rate controlling valve, a part of the detour pipe positioned on the upstream side of the flow rate controlling valve is connected to a heat source water inlet path of a water-cooled heat-pump air conditioning apparatus, a part of the detour pipe positioned on the downstream side of the flow rate controlling valve is connected to a heat source water outlet path of the water-cooled heat-pump air conditioning apparatus, an inlet water temperature detector configured to detect the heat source water inlet temperature of the water-cooled heat-pump air conditioning apparatus is provided, and also, an outlet water temperature detector configured to detect the heat source water outlet temperature of the water-cooled heat-pump air conditioning apparatus is provided, a control unit is further provided to adjust capability by increasing or decreasing the volume of the heat source water supplied to the water-cooled heat-pump air conditioning apparatus by controlling the water volume controlling valve on the basis of the heat source water inlet temperature and the heat source water outlet temperature detected by the water temperature detectors, and an open-close valve is provided in the heat source water circuit in a position between the upstream-side connection part and the downstream-side connection part of the detour pipe” (see Patent Literature 2, for example).